- Stage 1 (Run-in Period): Opioid doses are optimized, under a defined schedule, for up to a maximum of 10 days to ensure that all patients are on an optimized and stable regimen* prior to randomization. Following the run-in-period, patients undergo reassessment. Patients who have improved pain scores (i.e., < 4/10 on the visual-analogue score in the past 24 hours or < 5 McGill Sensory Scale Score) are taken off the study. Patients whose scores have not improved continue on to Stage 2 of the study.